Draggable peeking/fullscreen launcher with transparent background.

ash/shelf/shelf.cc

Index: ash/shelf/shelf.cc
diff --git a/ash/shelf/shelf.cc b/ash/shelf/shelf.cc
index 4209ba0d6bb0cc46461928e1de6980e22c55fd24..608ab85699f2bbcd076cb5c957bae8ef3e11129c 100644
--- a/ash/shelf/shelf.cc
+++ b/ash/shelf/shelf.cc
@@ -324,6 +324,10 @@ ShelfView* Shelf::GetShelfViewForTesting() {
   return shelf_widget_->shelf_view_for_testing();
 }
 
+void Shelf::OnAppListIsActive(bool is_active) {
+  shelf_layout_manager()->OnAppListIsActive(is_active);
+}
+
 void Shelf::WillDeleteShelfLayoutManager() {
   if (Shell::GetAshConfig() == Config::MASH) {
     // TODO(sky): this should be removed once Shell is used everywhere.